- Components of proteins
Proteins are composed of amino acid structures. Amino acids can be grouped into “essential” and “non-essential”.
- Food sources: Complete and Incomplete Proteins
“Complete proteins” contain all essential amino acids. Examples of complete protein food are mainly animal sourced, i.e. fish, meat, eggs and milk. “Incomplete proteins” do not contain all of essential amino acids. Examples of incomplete protein food are food such as fruits, vegetable, legumes etc.
- Function of proteins
Protein is a very important component of our diet. The human body requires protein for growth, development and maintenance of our cells and tissues. It is also necessary for the production of antibodies that prevent us from illnesses and infections.
- Risk of protein deficiency
- The lack of protein will result in muscle wasting. It may also lead to anemia and a slower recovery from injury.
- The lack of protein intake, especially in malnutrition-risk groups may result in conditions termed as Marasmus and Kwashiorkor. This is common in young children in developing countries.
- The elderly and vegetarians are at risk of developing protein deficiency and are therefore encouraged to take more protein.
- Having an array of protein intake variety, i.e. legumes plus nuts or legume plus grains to enables a vegetarian to have a complete intake of all types of essential amino acids.
- Optimal protein intake and the risk of excessive intake
For adults, the accepted safe level of protein intake is 0.83 g/kg body weight/day. Some studies have suggested 1.0 to 1.5g/kg/day of protein intake. Although a safe upper limit has not been identified, it is advised to avoid exceeding two times the safe intake. A study showed excess protein intake resulted in kidney stone formation and bone loss.
- Protein intake for Athletes
Athletes are advised to ensure that they increase their protein intake to 20–30% of their energy intake or 1.8–2.7 g/kg/day. Athletes are advised to consume protein food immediately after resistance exercise. This enables a maximum increase in muscle mass.
- Protein intake for pregnant mothers
Additional protein is required during pregnancy. The requirement for protein intake is 1.5 g/kg pregnant weight/day. The additional protein is required support the formation of maternal and fetal tissue formation during pregnancy.
- Three common types of protein powder
- Whey Protein: Whey protein is quickly digested, providing a rapid rise in amino acids that may help increase muscle mass and strength. It may also reduce appetite and promote fat loss.
- Casein Protein: Casein is a slow-digesting dairy protein that may reduce muscle protein breakdown and promote muscle mass growth and fat loss during calorie restriction.
- Pea Protein: Suitable for vegetarians. Pea protein may promote fullness and increase muscle growth as effectively as animal-based proteins.
- Dietary essentiality of “nutritionally non-essential amino acids” for animals and humans. YG Hou, YL Yin, GY Wu. (2015) Exp Biol Med (Maywood).
- Recommended nutrient intakes for Malaysia. National coordinating committee on food and nutrition. (2017) Ministry of Health Malaysia.
- The 7 best types of protein powder. F Spritzler (2018). Healthline. Online Web article. Web link:https://www.healthline.com/nutrition/best-protein-powder